Question 971252
a's 1 day work = 1/16 units
b's 1 day work = 1/20 units
So, in 4 days, total work by a and b = {{{4*((1/16)+(1/20))}}}
={{{(9/20)}}}units
{{{Balance work = 11/20}}} units
No. of further days taken by b = {{{(11/20)/(1/20)}}}
={{{11}}} days